Patent GB-413669-A (GB)
Title: Improvements in automatic voltage control of electric supply systems
IPC: G05F1/14
Filed: 1932-12-12
Abstract: 413,669. Automatic reversible motor regulators. JOHNSON & PHILLIPS, Ltd., Victoria Works, Charlton, and BLOOME, J., 20, Glenluce Road, Westcombe Park, both in London. Dec. 12, 1932, No. 35154. [Class 38 (iv).] An arrangement for the automatic regulation of A.C. voltage comprises a device, such as a choke 1 working at high or low flux density, or. a thermionic valve, having a non-linear currentvoltage characteristic for amplifying the voltage variation before application to electromagnetic switch apparatus which may comprise one or two solenoids 2 operating contacts IH or DC on increase or decrease of the voltage to be regulated, these contacts controlling the energization of electromagnetic clutches 9, 22 for transmitting movement from a power source 19 to means such as a tapping switch 17 for restoring the voltage of the system, the energization of the power source 19 being also controlled by the contacts IH, DC through means which prevent operation of the voltage regulating means 17 on transient voltages. Where the device 1 provides a large change in current therethrough for a small change in voltage it is connected in series with the solenoid 2 to terminals A, B connected to the voltage to be controlled. Where the device 1 provides a large change in voltage across its terminals for a small change in current it is connected to terminals A, B and in series with a resistance (not shown) to the voltage source, the coil 2 being connected across the device 1 and a regulating resistance 31 being connected across the coil 2. The rise and fall of the movable core 3 of the solenoid 2 operates pivoted weighted levers 8 and 26 which control contacts DC, IH respectively, an additional contact FE being provided to prevent completion of the circuit of IH whilst the contacts DC are closed. According to which of the contacts DC, IH is closed, clutch solenoids 22 or 9 are energized to lock latch members 23 or 10 on link arms 15, 13 to pins 11, 27 on a drum 17 operating a tapping switch or other means, e.g. of a transformer choke or resistance, controlling the voltage to be regulated. At the same time a contactor 12 is energized in series, a time delay dashpot 4 being provided thereon, the contactor controlling the energization of a coil 6 which raises a core 7 which, through arms 14, 13 or 15, 16 causes rotation of the tapping switch by shaft 20 by one tap in one or other direction depending upon which clutch member is closed A pin 19 on the armature 7 operates a lever 18 to open the circuit of the coil 6 and energize a coil 24 at contacts O, P, the coil 24 acting on an armature 25 to re-set the levers 8, 26. The action is repeated until the voltage is restored to normal. Levers 28, 29 controlling contacts RS, LM in series with the coils 22 and 9 project into the path of pins 27<a>, 11<a> on the drum 17 and prevent an excessive number of tap changes in any one direction. A time lag. device may be provided to slow down the movement of the plunger 3. The Provisional Specification describes an arrangement in which the floating plunger 3 is replaced by a floating ring of conducting material carried in a guide and arranged to operate contacts. Each contact DC or IH controls a separate lifting coil such as 6 which operates a separate core and lever mechanism to rotate the shaft 2 in one direction or the other without intermediate clutches. Alternatively, the shaft 2 may be rotated by a reversible electric motor energized for rotation in one direction or the other by one or other of the selector contacts DC or IH. Specification 27859/04, [Class 38], is referred to.